BACKGROUND
[0001] The embodiments described herein relate generally to electrical machines, and more
particularly, to an axial flux electrical machine including an integrated controller
for use in fluid circulating systems.
[0002] Many known commercial heating, ventilation, and air conditioning (HVAC) systems require
air propulsion units. In addition to providing movement of air for HVAC systems, air
propulsion units may be used in combination with condenser units and to supplement
other heat transfer operations. Some known air propulsion units include motor driven
fans. These fans include, for example, a centrifugal impeller type fan driven by a
radial flux motor. However, some known radial flux motors and their mounting components
extend a certain distance into the fan cavity. This restricts air flow through the
fan and yields aerodynamic losses that adversely affect fan performance.
[0003] Moving the air propulsion unit outside of the fan cavity causes an overall thickness
of the assembly to increase significantly and further requires that the fan be attached
to a shaft of the motor using various coupling mechanisms attached to the fan. These
known coupling mechanisms further add to the fan assembly thickness and introduce
weight and complexity to the fan assembly. Furthermore, the cost is increased in such
fan assemblies due to the increased part count required for coupling the fan to the
motor shaft.
[0004] In addition, many known air propulsion units include an integrated controller attached
to an end of the unit, thereby further increasing the thickness of the fan assembly.
To reduce the thickness of the air propulsion unit, many known units include complex
controller board arrangements and layout that can add cost and complexity to the unit,
and introduce localized heating from the heat generating components that is not adequately
dissipated.
BRIEF DESCRIPTION
[0005] In one aspect, a fluid circulating assembly having a rotation axis is provided. The
fluid circulating assembly includes a fan impeller having an inlet ring and a rear
plate that together define a central fan chamber. The assembly also includes an electrical
machine including a rotor assembly, a stator assembly, and a housing. The electrical
machine is coupled to the rear plate such that the electrical machine is positioned
entirely outside the central fan chamber. The housing includes a plurality of fins
on a side of the housing opposite the rear plate. The plurality of fins extend axially
away from the stator assembly. Furthermore, the assembly includes a duct coupled to
the housing. The duct covers a portion of the fins and extends radially outward from
the housing to the rear plate and towards an outer edge of the rear plate. The duct
is configured to channel air over the portion of the fins to facilitate cooling the
electrical machine.
[0006] In another aspect, a method for assembling a fluid circulating assembly having a
rotation axis is provided. The method includes providing a fan impeller including
an inlet ring and a rear plate that together define a central fan chamber. The method
also includes coupling an electrical machine to the rear plate such that the electrical
machine is positioned entirely outside the central fan chamber. The electrical machine
includes a rotor assembly, a stator assembly, and a housing. The housing includes
a plurality of fins on a side of the housing opposite the rear plate. The plurality
of fins extend axially away from the stator assembly. The method further includes
coupling a duct to the housing. The duct covers a portion of the fins and extends
radially outward from the housing to the rear plate and towards an outer edge of the
rear plate. The duct is configured to channel air over the portion of the fins to
facilitate cooling the electrical machine.
[0007] In yet another aspect, a fluid circulating assembly is provided. The fluid circulating
assembly includes an electrical machine. The electrical machine includes a rotor assembly,
a stator assembly, and a housing. The housing includes an endshield. The endshield
includes an annular center section configured to enclose the stator assembly, a plurality
of fins extending axially away from the stator assembly, and a plurality of axially
extending T-shaped T-slots spaced about a perimeter of the annular center section
of the endshield.
[0008] In yet another aspect, a method of assembling a fluid circulating assembly is provided.
The method includes providing an electrical machine including a housing having a plurality
of axially extending T-slots spaced about a perimeter of the housing. The method also
includes slidingly coupling a T-nut to each one of the plurality of axially extending
T-slots. Furthermore, the method includes releasably coupling each respective T-nut
to a support bracket using at least one fastener. This enables the electrical machine
to be slidingly coupled to the support bracket via the T-nuts at an infinite number
of locations along a length of the plurality of axially extending T-slots.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009]
FIG. 1 is a schematic perspective of an exemplary fluid circulating assembly;
FIG. 2 is a cross-sectional view of the fluid circulating assembly taken along line
2-2 of FIG. 1;
FIG. 3 is an enlarged view of a portion of FIG. 2 identified by box 3, showing an
electrical machine of the fluid circulating assembly without a fan impeller;
FIG. 4 is an exploded view of the electrical machine shown in FIG. 3;
FIG. 5 is an end view of a housing looking axially along a center axis toward an endshield;
FIG. 6 is an exploded view of the housing of FIG. 5 looking toward a cover plate from
the endshield;
FIG. 7 is an exploded view of the housing of FIG. 5 looking toward the endshield from
the cover plate;
FIG. 8 is an enlarged view of a portion of FIG. 3 identified by box 8;
FIG. 9 is an exploded view of a hub drive for use with the electrical machine shown
in FIG. 3;
FIG. 10 is a front view of the hub drive shown in FIG. 9;
FIG. 11 is a side view of the hub drive shown in FIG. 9;
FIG. 12 is an exploded view of a mounting system for the electrical machine shown
in FIG. 3;
FIG. 13 is a side view of the fluid circulating assembly shown in FIG. 1 coupled to
a support bracket and positioned at an outward extent away from an inlet nozzle support
plate;
FIG. 14 is a side view of the fluid circulating assembly shown in FIG. 1 coupled to
the support bracket and positioned at an inward extent toward the inlet nozzle support
plate;
Fig. 15 is a schematic perspective of the fluid circulating assembly shown in FIG.
1 mounted to the support bracket and including cooling ducts;
FIG. 16 is an exploded perspective view of the endshield shown in FIG. 5 having a
controller assembly attached thererto;
FIG. 17 is an exploded perspective view of the endshield shown in FIG. 5 having an
alternative embodiment of the controller assembly attached thererto;
FIG. 18 is a cross-sectional view of an alternative fluid circulating assembly; and
FIG. 19 is a schematic perspective of the alternative fluid circulating assembly shown
in FIG. 18, showing a shaft/hub assembly for coupling a fan impeller to the electrical
machine shown in FIG. 3.
[0010] Although specific features of various embodiments may be shown in some drawings and
not in others, this is for convenience only. Any feature of any drawing may be referenced
and/or claimed in combination with any feature of any other drawing.
DETAILED DESCRIPTION
[0011] FIG. 1 is a schematic perspective of an exemplary fluid circulating assembly 10.
FIG. 2 is a cross-sectional view of fluid circulating assembly 10 taken along line
2-2 of FIG. 1. In the exemplary embodiment, fluid circulating assembly 10 generates
a flow of air in a forced air system, for example, without limitation, a residential
or commercial heating, ventilation, and air conditioning (HVAC) system. Alternatively,
fluid circulating assembly 10 generates a fluid flow in any type of fluid circulating
system that enables fluid circulating assembly 10 to function as described herein.
In the exemplary embodiment, fluid circulating assembly 10 includes a fan impeller
12 coupled to an electrical machine 14. In the exemplary embodiment, electrical machine
14 is an electric motor, and more specifically, an axial flux electric motor, although,
electrical machine 14 may function as either an electric motor or an electric generator.
Furthermore, fan impeller 12 is a centrifugal fan impeller, although, impeller 12
can be a pump impeller.
[0012] In the exemplary embodiment, fan impeller 12 includes a plurality of fan blades 16
(blades). Blades 16 are attached between a rear plate 18 and an inlet ring 20 (or
front plate). Inlet ring 20 includes a central air inlet 22. In the exemplary embodiment,
fan impeller 12 is a backward curved plug fan. Alternatively, fan impeller 12 may
have any suitable blade shape or configuration that enables fluid circulating assembly
10 to operate as described herein, for example, without limitation, a backward curved
blade, an airfoil blade, a backward inclined blade, a forward curved blade, and a
radial blade.
[0013] In the exemplary embodiment, rear plate 18 and inlet ring 20 are coaxial, or substantially
coaxial, and rotate about a center axis 24. Blades 16 are attached to rear plate 18
and/or inlet ring 20 such that each blade 16 extends between rear plate 18 and inlet
ring 20. In the exemplary embodiment, each blade 16 is attached to rear plate 18 and
inlet ring 20 by mechanical bonding, such as welding. Alternatively, each blade 16
is attached to rear plate 18 and/or inlet ring 20 via mechanical fasteners, for example,
without limitation, rivets, or via features formed in rear plate 18 and/or inlet ring
20 such as an opening, for example, without limitation, a groove or a slot configured
to restrict an amount of movement of blade 16 between rear plate 18 and inlet ring
20 while enabling each blade 16 to operate as described herein.
[0014] In the exemplary embodiment, during operation, air enters fluid circulating assembly
10 substantially axially along center axis 24 through central air inlet 22 and is
deflected radially outward toward blades 16. Blades 16 are configured to draw the
air through inlet 22 into a central chamber 28 of fan impeller 12, i.e., blades 16
pull in air along center axis 24 and eject the air radially outward through outlet
channels 26, where each outlet channel 26 is located between adjacent blades 16. The
air passes between blades 16 and is pushed outward through outlet channels 26 due
to centrifugal force generated by the rotating blades 16. Blades 16 are suitably fabricated
from any number of materials, including sheet metal, plastic, or a flexible or compliant
material. Alternatively, blades 16 are fabricated from a combination of materials
such as attaching a flexible or compliant material to a rigid material, or any suitable
material or material combination that enables blades 16 to operate as described herein.
[0015] FIG. 3 is an enlarged view of a portion of FIG. 2 identified by box 3, showing electrical
machine 14 without fan impeller 12. FIG. 4 is an exploded view of electrical machine
14. In the exemplary embodiment, electrical machine 14 is an axial flux electric motor
configured to rotate fan impeller 12 about center axis 24. Electrical machine 14 includes
a stator assembly 30, a rotor assembly 32, and a pair of bearing assemblies 34a, 34b
coupled radially therebetween. Stator assembly 30, rotor assembly 32, and bearing
assemblies 34a, 34b are positioned concentrically, each including a central opening
35 oriented about center axis 24.
[0016] Stator assembly 30 includes a stator core 36 that includes a plurality of circumferentially-spaced
stator teeth 38 that extend axially, substantially parallel to center axis 24. In
the exemplary embodiment, stator core 36 is a laminated core. As defined herein, the
laminated core is radially laminated, e.g., fabricated with a ribbon of material wound
into a core, or a series of concentric rings stacked one inside the other to create
a core of material, for example, soft iron or silicon steel. Alternatively, stator
core 36 may be a solid core stator. A solid core can be a complete, one-piece component,
or can include multiple non-laminated sections coupled together to form a complete
solid core. Stator core 36 is fabricated from a magnetic material, such as, for example,
a Soft Magnetic Alloy (SMA) or a Soft Magnetic Composite (SMC) material. Alternatively,
stator core 36 is fabricated from any ferromagnetic material that enables electrical
machine 14 to function as described herein, such as, for example, steel or a steel
alloy. The use of SMA or SMC materials in a solid core enable 3-dimensional flux paths
and facilitate reducing high frequency losses (e.g., losses at frequencies above 60
Hz) when compared with laminated stator cores. The use of SMC or SMA materials also
facilitates increasing control of an air gap 39, which facilitates improving performance
and minimizing noise.
[0017] Between each pair of adjacent stator teeth 38 is a slot 40. Each stator tooth 38
is configured to receive one of a plurality of insulating bobbins 42 that includes
a copper winding 44 would around an outer surface of each respective bobbin 42. Alternatively,
each stator tooth 38 includes copper winding 44 without bobbin 42. Electrical machine
14 can include one copper winding 44 per stator tooth 38 or one copper winding 44
positioned on every other stator tooth 38. Copper windings 44 are electrically coupled
to a controller assembly 46 for receiving electrical current thereby inducing an electromagnetic
field about a pole of stator core 36. Controller assembly 46 is configured to apply
a voltage to one or more of copper windings 44 at a time for commutating copper windings
44 in a preselected sequence to rotate rotor assembly 32 about center axis 24. In
the exemplary embodiment, electrical current is a three-phase alternating current
(AC). Alternatively, the current is any type of electrical current that enables electrical
machine 14 to function as described herein. In the exemplary embodiment, controller
assembly 46 functions to both accelerate and decelerate rotor assembly 32.
[0018] In the exemplary embodiment, rotor assembly 32 includes a rotor disk assembly 48
having an axially inner surface 50 and a radially inner wall 52 that at least partially
defines opening 35. Rotor assembly 32 also includes a plurality of permanent magnets
54 coupled to inner surface 50 of rotor disk assembly 48. In one suitable embodiment,
magnets 54 are coupled to rotor disk assembly 48 using an adhesive. Alternatively,
magnets 54 are coupled to rotor disk assembly 48 by a magnet retaining ring or any
other retention method that enables electrical machine 14 to function as described
herein. In the exemplary embodiment, permanent magnets 54 are symmetrical, which facilitates
manufacturing by enabling a single magnet design for use with each magnet 54. Furthermore,
each magnet 54 has a substantially flat profile which facilitates reducing waste during
manufacturing, and therefore, facilitates reducing manufacturing cost. In the exemplary
embodiment, permanent magnets 54 are neodymium magnets. Alternatively, any suitable
permanent magnet material may be included that enables electrical machine 14 to function
as described herein, for example, without limitation, Samarium Cobalt and Ferrite.
Rotor assembly 32 is rotatable within electrical machine 14, and more specifically,
rotatable within bearing assemblies 34a, 34b about center axis 24.
[0019] In the exemplary embodiment, rotor disk assembly 48 is fabricated from a solid metal
material, for example, without limitation, steel or iron. Alternatively, rotor disk
assembly 48 is fabricated from, for example, an SMA material, an SMC material, or
a powdered ferrite material, using a sintering process. Similarly, as described above,
stator core 36 is fabricated from a material that enables magnetic attraction between
permanent magnets 54 and stator core 36 to facilitate retaining rotor disk assembly
48 and bearing assemblies 34a, 34b in place within electrical machine 14 such that
electrical machine 14 does not require a shaft. Rotor disk assembly 48 includes a
shaft portion 49 that includes a step 51 configured to facilitate holding bearing
assembly 34a in place. Shaft portion 49 includes a diameter (not shown) configured
to corresponding a diameter of bearing assemblies 34a, 34b. Furthermore, rotor disk
assembly 48 includes a ring-shaped axially extending flange 53 that extends outward
from rotor disk assembly 48 toward fan impeller 12 (not shown in FIG. 4).
[0020] In the exemplary embodiment, electrical machine 14 includes housing 56 configured
to provide a protective covering for electrical machine 14 and controller assembly
46. In the exemplary embodiment, housing 56 includes an endshield 58 having an integrated
flange 60 that extends axially towards rear plate 18 of fan impeller 12 (shown in
FIGS. 1 and 2) from a perimeter of endshield 58. Furthermore, housing 56 includes
a cover plate 62 that is configured to couple to flange 60, thereby enclosing components
of electrical machine 14 within housing 56. Housing 56 is configured to maintain a
stationary position of stator assembly 30, bearing assemblies 34a, 34b, and controller
assembly 46 during rotation of fan impeller 12 and rotor assembly 32.
[0021] Housing 56 is shown in more detail in FIGS. 5-7. Endshield 58 is configured with
two distinct sides; a component engaging side 100 as best shown in FIG. 7 and a component
cooling side 102 as best shown in FIGS. 5 and 6. Specifically, FIG. 5 is an end view
of housing 56 looking axially along center axis 24 toward endshield 58, FIG. 6 is
an exploded view of housing 56 looking toward cover plate 62 from endshield 58, and
FIG. 7 is an exploded view of housing 56 looking toward endshield 58 from cover plate
62.
[0022] In the exemplary embodiment, endshield 58 is cloverleaf-shaped, having four extension
portions 64 extending radially outward from an annular center section 66. Alternatively,
endshield 58 has fewer or more than four extension portion 64 and can have any shape
that enables endshield 58 to function as described herein. Each extension portion
64 is configured to retain a component of controller assembly 46 therein. Center section
66 includes a bearing locator 68 extending from an inner surface 70 of endshield 58
that facilitates retaining bearing assemblies 34a, 34b (shown in FIG. 4) in place.
Bearing locator 68 includes opening 35 that is formed as a stepped bore having a first
step 72 and a second step 74 defining increasingly smaller bore diameters. Bearing
assembly 34a is seated in opening 35 in the smaller diameter portion defined by second
step 74. A bearing retainer plate 76 is secured to endshield 58 to secure bearing
34a in place. Retainer plate 76 is attached to endshield 58 using a plurality of mechanical
fasteners 80. Bearing assembly 34b is seated in opening 35 in the largest diameter
portion defined by first step 72. Bearing locator 68 engages and locates each bearing
assembly 34a, 34b by engaging an outer race portion (not shown) to position and secure
bearing assemblies 34a, 34b such that bearing assemblies 34a, 34b are positioned radially
inward from and concentric with stator assembly 30 (shown in FIG. 4).
[0023] In the exemplary embodiment, endshield 58 includes a plurality of cooling fins 78
(best shown in FIG. 6) extending from component cooling side 102. Fins 78 facilitate
cooling electrical machine 14 and extend generally radially outward from annular center
section 66. Furthermore, fins 78 extend axially outward from endshield 58. In the
exemplary embodiment, fins 78 are formed in substantially parallel groups that extend
generally radially outward along each extension portions 64, where each group of fins
78 is formed substantially transverse to each respective adjacent group of fins 78.
Alternatively, fins 78 can arrangement in any arrangement that enables electrical
machine 14 to function as described herein.
[0024] In the exemplary embodiment, a flange 82 extends axially inward from surface 70 a
distance substantially equal to a length of each stator tooth 38. Flange 82 facilitates
substantially isolating stator assembly 30 from controller assembly 46 within endshield
58. This facilitates reducing electrical interference or short circuiting between
the assemblies. In one embodiment, endshield 58 is fabricated from cast aluminum.
Alternatively, endshield 58 is fabricated from any material that enables endshield
58 to function as described herein, for example, without limitation, an aluminum-tin-nickel
alloy, or steel. Further, in the exemplary embodiment, endshield 58 is a single piece
cast component. Alternatively, endshield 58 is fabricated as several separate components
that can be coupled together to form endshield 58.
[0025] In the exemplary embodiment, each of extension portions 64 includes pockets 104 of
various shapes and sizes. Pockets 104 are formed in inner surface 70 and extend axially
outward toward fins 78. Each one of pockets 104 is configured to conform to a specific
shape of a component of controller assembly 46 to enable controller assembly 46 to
be enclosed within housing 56. Furthermore, each of extension portions 64 include
a plurality of mounting bosses 106 configured to accept a mechanical fastener to hold
a circuit board (not shown in FIGS. 5-7) of controller assembly 46.
[0026] In the exemplary embodiment, at least one of extension portions 64 includes one or
more power inlet openings 108. Inlet openings 108 are circular in shape and extend
through flange 60 of endshield 58. In the exemplary embodiment, one of extension portions
64 includes three inlet openings 108 extending through the outer most extent of extension
portion 64. Inlet openings 108 are configured to accept an end user's electrical power
supply lines for attaching to controller assembly 46. In alterative embodiments, inlet
openings 108 and be any shape and any number that enables endshield 58 to function
as described herein. In the exemplary embodiment, the extension portion 64 that includes
inlet openings 108 is also configured with a terminal cover 110. Terminal cover 110
is fabricated to be a removable portion of endshield 58 to facilitate access to controller
assembly 46 for attaching an end user's electrical power supply lines to controller
assembly 46 without the need to completely disassemble electrical machine 14. In the
exemplary embodiment, terminal cover 110 extends about a perimeter of the respective
extension portion 64 and is offset radially outward a distance from center section
66 of endshield 58. Extension portion 64 includes a lip 112 having a plurality of
mounting holes 114 for receiving mechanical fasteners 116. Terminal cover 110 includes
a plurality of holes 118 that correspond to mounting holes 114 for receiving mechanical
fasteners 116. In alternative embodiments, terminal cover 110 can have any size and
shape that enables endshield 58 to function as described herein.
[0027] In the exemplary embodiment, housing 56 also includes cover plate 62, which is shaped
to conform to the perimeter shape of endshield 58. In the exemplary embodiment, cover
plate 62 is coupled to endshield 58 using a plurality of mechanical fasteners 84.
Cover plate 62 includes an annular inner flange 86 that defines an opening 88 in cover
plate 62. Inner flange 86 extends axially away from both an outer surface 90 and an
inner surface 92 of cover plate 62. Inner flange 86 is configured facilitate reducing
flexing of cover plate 62 and to provide and inner most structure for a sealing channel
94. Sealing channel 94 is formed on inner surface 92 and is defined by inner flange
86 and an outer flange 96 that has a larger diameter and is radially offset from inner
flange 86. Channel 94 is shaped and configured to correspond to flange 53 of rotor
disk assembly 48.
[0028] FIG. 8 is an enlarged view of a portion of FIG. 3 identified by box 8. In the exemplary
embodiment, sealing channel 94 and flange 53 cooperate to form a tortuous sealing
path between rotor disk assembly 48 and housing 56. In the exemplary embodiment, channel
94 includes a plurality of fiber filaments 121. Each filament 121 is a fine, hair-like
structure fabricated from an electrically conductive material. For example, without
limitation, filaments 121 can be fabricated from carbon fiber, stainless steel fiber,
conductive acrylic fiber, or any other conductive fiber-type filament that enables
filaments 121 to function as described herein. In the exemplary embodiment, filaments
121 are adhered directly or indirectly to a carrier structure (not shown) and positioned
within sealing channel 94. In operation, the filaments 121 are in electrically conductive
contact with rotor disk assembly flange 53 to facilitate grounding rotor disk assembly
48 to reduce electric charges that accumulate on rotor disk assembly 48.
[0029] With reference to FIGS. 3 and 4, in the exemplary embodiment, stator assembly 30
is coupled to housing 56 via a plurality of fasteners 120 extending through an axially
outermost surface 122 of endshield 58. Furthermore, each one of bearings 34a, 34b
is coupled to bearing locator 68 of endshield 58 and bearing retainer plate 76 is
secured to endshield 58 to secure bearing 34a in place. Rotor assembly 32 is positioned
within housing 56 such that shaft portion 49 extends through bearing assemblies 34a,
34b. In particular, rotor disk assembly 48 seats against bearing assembly 34b to facilitate
holding bearing assembly 34b in place against step 72, and step 51 of shaft portion
49 seats against bearing assembly 34a to facilitate holding bearing assembly 34a in
place against bearing retainer plate 76. A shaft seal 124 is pressed into a center
opening of bearing retainer plate 76 to facilitate keeping debris from entering electrical
machine 14, and in particular bearing assemblies 34a, 34b. The location of bearings
34a, 34b in endshield 58 is configured to control the width of air gap 39, which facilitates
improving performance and minimizing noise. Cover plate 62 is coupled to endshield
58 to complete assembly of housing 56 and to enclose electrical machine 14.
[0030] FIG. 9 is an exploded view of a hub drive 126 for use with electrical machine 14.
FIG. 10 is a front view of hub drive 126 and FIG. 11 is a side view of hub drive 126.
In the exemplary embodiment, hub drive 126 is ring-shaped and has an outer diameter
D1 that is smaller than an inner diameter of flange 86 of cover plate 62. Hub drive
126 includes a plurality of fingers 128 extending radially inward from an inner surface
130 of hub drive 126. Each finger 128 is generally triangular in shape and includes
a mounting hole 132 configured to correspond to a respective mounting hole in rotor
disk assembly 48. In the exemplary embodiment, hub drive 126 includes an axially extending
lip 134 that extends away from rotor disk assembly 48. Lip 134 has a diameter that
corresponds to an opening in fan impeller 12, where lip 134 is configured to locate
fan impeller 12 substantially concentric with electrical machine 14 to facilitate
reducing imbalances and vibrations. In the exemplary embodiment, hub drive 126 includes
a substantially flat and smooth face 136 configured to mate directly to rear plate
18 of fan impeller 12. Alternatively, face 136 has grooves, channels, or other features
form therein and configured to facilitate moving air through opening 35 in rotor shaft
portion 49.
[0031] In the exemplary embodiment, hub drive 126 includes a plurality of axially extending
mounting holes 138 formed in face 136. Holes 138 are configured to corresponding to
respective mounting holes formed in rear plate 18 of fan impeller 12 and to receive
fasteners. In the exemplary embodiment, when mounted to rotor disk assembly 48, as
best shown in FIG. 3, hub drive 126 has a thickness such that face 136 is positioned
axially outward from an extent of flange 86 of cover plate 62 to enable fan impeller
(not shown in FIG. 3) to rotate about center axis 24 without interfering with any
portion of housing 56. In an alternative embodiment, rotor disk assembly 48 is fabricated
with the features of hub drive 126, such that rotor disk assembly 48 can be coupled
directly to rear plate 18 of fan impeller 12 without the need to use hub drive 126
therebetween.
[0032] FIG. 12 is an exploded view of a mounting system for electrical machine 14. In the
exemplary embodiment, a support bracket 150 is coupled to electrical machine 14 via
a plurality of T-nuts 152 and fasteners 154 that mount to corresponding T-slots 156
formed in housing 56. With reference back to FIGS. 5 and 6, endshield 58 of housing
56 includes a plurality of axially extending T-slots 156. In the exemplary embodiment,
endshield 58 includes four T-slots 156, each located in a respective intersection
between two adjacent extension portions 64. Each T-slot 156 is identical in size and
shape, having a T-shaped cross-section with the narrow opening of each T-slot 156
facing radially outward from center section 66 of endshield 58. As described above,
each T-slot 156 extends axially such that each T-slot 156 is substantially parallel
to center axis 24. Such a configuration enables electrical machine 14 to be located
in an infinite number of locations between the two extents of T-slots 156. Each T-nut
152 is located within a respective T-slot 156 and connected to a respective support
arm of support bracket 150 by a pair of fasteners 154. When fasteners 154 are loosely
affixed to T-nuts 152, electrical machine 14 can slide along the entire length of
T-slots 156. Fasteners 154 are turned to tighten with T-nuts 152 to affix electrical
machine 14 in any one of an infinite number of positions within the T-slots 156.
[0033] FIG. 13 is a side view of fluid circulating assembly 10 coupled to support bracket
150 and positioned at an outward extent away from an inlet nozzle support plate 158.
FIG. 14 is a side view of fluid circulating assembly 10 coupled to support bracket
150 and positioned at an inward extent toward inlet nozzle support plate 158. In the
exemplary embodiment, T-nuts 152 and fasteners 154 enable fluid circulating assembly
10 to be accurately positioned with respect to inlet nozzle support plate 158, to
enable a user to position fluid circulating assembly 10 at an optimum location based
on use conditions. Support bracket 150 is coupled to inlet nozzle support plate 158
via its mounting arms. As shown in FIG. 13, fluid circulating assembly 10 is positioned
at its outward extent of T-slots 156, such that support bracket 150 does not contact
fan impeller 12, yet a gap distance 160 is defined between central air inlet 22 of
impeller 12 and inlet nozzle 162 of inlet nozzle support plate 158. Moreover, as shown
in FIG. 14, fluid circulating assembly 10 is positioned at its inward extent of T-slots
156, such that central air inlet 22 of impeller 12 is positioned beyond inlet nozzle
162 of inlet nozzle support plate 158, and no gap distance 160 is defined. The use
of T-nuts 152 enables fluid circulating assembly 10 to be positioned in any one of
an infinite number of positions between the inward and outward extents of T-slots
156.
[0034] Fig. 15 is a schematic perspective of fluid circulating assembly 10 mounted to support
bracket 150 and including cooling ducts 170. In the exemplary embodiment, electrical
machine 14 includes a plurality of cooling ducts 170 configured to be secured to endshield
58 of electrical machine 14 using, for example, without limitation, mechanical fasteners
coupled to endshield 58. An advantage provided by ducts 170 is that they are lightweight,
easy to install, and can be used to convert air ejected by fan impeller 12 to cool
electrical machine 14. Each duct 170 is securely coupled to one of extension portions
64 of housing 56 and extends over fins 78 of the respective extension portion 64.
Each duct 170 is substantially U-shaped in cross-section and forms a converging taper
extending radially outward between center section 66 of endshield 58 and an outer
edge of rear plate 18. At the outer edge of rear plate 18, duct 170 turns approximately
90 degrees and extends a predefined distance 172 past the edge of rear plate 18. This
enables duct 170 to capture a portion of air ejected by fan impeller 12 and direct
it over fins 78 to facilitate cooling electrical machine 14.
[0035] In an alternative embodiment, each duct 170 is substantially U-shaped in cross-section
and forms a converging taper that extends radially outward between center section
66 of endshield 58 and an outer edge of rear plate 18, where duct 170 terminates,
forming a radially extending U-shaped channel over fins 78 and extension portions
64. In such an embodiment, an axial fan is coupled to rotor shaft portion 49 and positioned
proximate fins 78 of center section 66, such that air is forced over fins 78 and through
ducts 170. In such an embodiment, axial fan is turned by electrical machine 14.
[0036] Ducts 170 are suitably fabricated from any number of materials, including a plastic
sheet material or other sheet material. For example, in one suitable embodiment, ducts
170 are formed by a molding, forming, or extruding process used for fabricating parts
from thermoplastic or thermosetting plastic materials and/or metals. Alternatively,
ducts 170 are fabricated from a combination of materials such as attaching two or
more sheet components together to form ducts 170. Ducts 170, however, are constructed
of any suitable material, such as metal, that permits ducts 170 to function as described
herein.
[0037] FIG. 16 is an exploded perspective view of endshield 58 having controller assembly
46 attached thererto. As described above, controller assembly 46 is coupled within
housing 56 adjacent to stator assembly 30 and rotor assembly 32, such that controller
assembly 46 is positioned radially outward from stator assembly 30. Controller assembly
46 includes more than one circuit board. In the exemplary embodiment, controller assembly
46 includes three circuit boards; a user interface board 200, a rectifier board 202,
and an inverter board 204. Alternatively, controller assembly 46 includes fewer or
more circuit boards. For example, without limitation, in one alternative embodiment
shown in FIG. 17, controller assembly 46 includes four circuit boards; one located
in each extension portion 64, including user interface board 200, rectifier board
202, inverter board 204, and an AC input board 206. In one suitable embodiment, controller
assembly 46 includes two circuit boards such that power can be supplied directly to
inverter board 204, thereby eliminating the need for rectifier board 202 and user
interface board 200. Moreover, in another suitable embodiment, a single circuit board
is used with controller assembly 46, such that all functions of controller assembly
46 is integrated onto the single circuit board.
[0038] In the exemplary embodiment, user interface board 200, rectifier board 202, and inverter
board 204, i.e., controller assembly 46, are oriented substantially planar with respect
to a back plane of stator assembly 30. As such, controller assembly 46 is not oriented
axially with respect to electrical machine 14. Alternatively, one or more of boards
200, 202, and 204, can be arranged perpendicular to an axial plane of stator assembly
30, thereby enabling alternative packaging layouts. Advantages of breaking controller
assembly 46 into modular board components, includes: enabling controller assembly
46 to be favorably arranged around the outside diameter of stator assembly 30; enabling
controller assembly 46 to share a common heat sink, i.e., endshield 58, with stator
assembly 30; arranging the boards of controller assembly 46 to separate heat making
devices onto separate boards; and separating controller assembly 46 into major functions
which can be built on separate boards.
[0039] In the exemplary embodiment, each one of boards 200, 202, and 204 is substantially
rectangular in shape and is sized to fit a respective extension portion 64 of endshield
58. This facilitates reducing the cost of manufacturing different shape boards, for
example, circular-shaped boards, that are used in axially-stacked motors. Alternatively,
boards 200, 202, and 204 can be fabricated in any number of shapes that facilitates
operation of fluid circulating assembly 10 as described herein. In the exemplary embodiment,
boards 200, 202, and 204 are distributed around stator assembly 30 and are separated
into separate functions built on a respective one boards 200, 202, and 204. Using
separate boards 200, 202, and 204 having distinct functions enables the individual
boards of controller assembly 46 to be updated without affecting the entire controller
assembly 46. Such updates can be necessitated by end users, new components, cost savings,
or obsolescence of current components. Furthermore, by separating controller assembly
46 into discrete circuit boards, the circuit sections can be arranged in different
configurations to alter the final shape of electrical machine 14 and controller assembly
46. In addition, separating boards 200, 202, and 204 into separate functions facilitates
spreading the heat making components of controller assembly 46 apart to facilitate
cooling of controller assembly 46.
[0040] In the exemplary embodiment, user interface board 200 is coupled to the extension
portion 64 having inlet openings 108 and terminal cover 110. User interface board
200 includes a plurality of mounting holes 210 formed therethrough, including one
mounting hole 210 in each corner of board 200. A fastener 212 is passed through each
hole 210 and coupled to endshield 58 to secure board 200 in place. The user then attaches
his inputs to user interface board 200, for example, without limitation, an AC input
connection, a serial communication connection, and any additional discrete input/output
digital or analog connections. User interface board 200 outputs the AC current and
a serial communication signal and receives a low voltage direct current (DC) signal
from inverter board 204 to power board 200.
[0041] Rectifier board 202 is coupled to an extension portion 64 adjacent user interface
board 200. Rectifier board 202 includes a plurality of mounting holes 210 formed therethrough,
including one mounting hole 210 in each corner of board 202. A fastener 212 is passed
through each hole 210 and coupled to endshield 58 to secure board 202 in place. Rectifier
board 202 receives the AC current from user interface board 200, and outputs a high
current DC signal, via any one of a standard connector type (not shown).
[0042] Inverter board 204 is coupled to an extension portion 64 adjacent rectifier board
202. Inverter board 204 includes a plurality of mounting holes 210 formed therethrough,
including one mounting hole 210 in each corner of board 204. A fastener 212 is passed
through each hole 210 and coupled to endshield 58 to secure board 204 in place. Invertor
board 204 receives the high current DC signal from rectifier board 202 and the serial
communication from user interface board 200, and outputs an AC signal to stator assembly
30 to drive electrical machine 14 and a low voltage DC signal to user interface board
200. The input and output connections on invertor board 204 are any one of a standard
connector type (not shown).
[0043] In alternative embodiments, if the power requirements for electrical machine 14 are
such that any one board generates excessive heat, the modular configuration of controller
assembly 46 enables each of the circuit boards to be reconfigured to spread the heat
generating components around stator assembly 30. For example, in one suitable embodiment,
rectifier board 202 includes a bridge rectifier and a common mode choke, each of which
can generate heat. If the heat generated is determined to be excessive, rectifier
board 202 can be split into two separate boards, such that the bridge rectifier and
the common mode choke are placed on respective discrete boards. Each board can then
be placed into a separate extension portion 64 of endshield 58.
[0044] As shown in FIG. 2, electrical machine 14 is coupled to fan impeller 12 such that
electrical machine 14 is positioned entirely outside fan chamber 28, i.e., no portion
of electrical machine 14 extends through rear plate 18 to intrude into chamber 28.
Thus, air is able to flow through chamber 28 free of disturbances and without being
directed around electrical machine 14, as is the case in at least some known fan assemblies
having radial flux motors. Such interference generally results in a loss of fan efficiency.
Therefore, zero intrusion of electrical machine 14 into chamber 28 prevents such a
loss in efficiency and provides for an increase in efficiency of fluid circulating
assembly 10 as compared to at least some known fluid circulating assemblies having
radial flux motors that extend a significant distance into the fan chamber.
[0045] In the exemplary embodiment, as best shown in FIG. 2, electrical machine 14 does
not include a shaft or a shaft hub assembly to couple electrical machine 14 to fan
impeller 12. Rather, electrical machine 14 is coupled directly to rear plate 18 of
fan impeller 12 via drive hub 126 to facilitate rotation of fan impeller 12 about
center axis 24. More specifically, drive hub 126 is coupled directly to rotor disk
assembly 48, and rear plate 18 is coupled directly to drive hub 126 via fasteners
164 threaded through corresponding openings (not shown) formed in rear plate 18. Alternatively,
rotor disk assembly 48 can be fabricated to couple directly to rear plate 18, such
that drive hub 126 is not needed. In another embodiment, rotor disk assembly 48 is
coupled to rear plate 18 in any manner that facilitates operation of fluid circulating
assembly 10 as described herein.
[0046] FIG. 18 is a cross-sectional view of an alternative fluid circulating assembly 174.
FIG. 19 is a schematic perspective of the alternative fluid circulating assembly shown
in FIG. 18, showing a shaft/hub assembly 176 for coupling fan impeller 12 to electrical
machine 14. In this embodiment, electrical machine 14 includes a shaft 178 coupled
to radially inner wall 52 of rotor disk assembly 48. In the exemplary embodiment,
shaft 178 is sized to provide an interference fit with inner wall 52. A keyway 180
is formed in shaft 178 for keying shaft 178 to radially inner wall 52 of rotor disk
assembly 48. In alternative embodiments, shaft 178 is coupled to radially inner wall
52 of rotor disk assembly 48 in any manner that enables fluid circulating assembly
174 to function as described herein. In the embodiment shown in FIG. 18 and 19, shaft
178 extends axially away from electrical machine 14 into chamber 28 of fan impeller
12. Shaft/hub assembly 176 includes a hub flange 182 coupled to fan impeller 12 via
a plurality of fastener 164. Hub flange 182 includes a generally cylindrical hub portion
184 and an annular flange portion 186 extending radially outward from hub portion
184 and located at an end of the hub portion. Hub flange 182 includes a hole (not
shown) that is concentric with hub portion 184 and configured to couple to shaft 178.
In this embodiment, shaft 178 is keyed to hub flange 182 and forms an interference
fit with the hole (not shown) provided through hub flange 182. Hub flange 182 also
includes a plurality of fasteners openings (not shown) configured to receive fasteners
164 for coupling to fan impeller 12. In alternative embodiments, shaft 178 is coupled
to hub flange 182 in any manner that enables fluid circulating assembly 174 to function
as described herein.
[0047] In operation, copper windings 44 are coupled to stator core 36 and are energized
in a predetermined sequence by controller assembly 46. Cooper winding's 44 facilitates
generating an axial magnetic field that moves in one of a clockwise and counterclockwise
direction around stator core 36, depending on the predetermined sequence in which
copper windings 44 are energized. The moving magnetic field intersects with a flux
field generated by permanent magnets 54 to generate a torque that causes rotor assembly
32 to rotate about center axis 24 relative to stator assembly 30. The generated torques
is a direct function of the strength, or intensity, of the magnetic field interactions
between cooper windings 44 and permanent magnets 54. Because rotor disk assembly 48
is coupled directly to rear plate 18 of fan impeller 12, rotation of rotor disk assembly
48 facilitates rotation of fan impeller 12.
[0048] The present disclosure provides a fluid circulating assembly with improved structural
designs that improves the air flow entering, passing through, and downstream of the
assembly. More specifically, a fluid circulating assembly is disclosed that includes
an electrical machine that is coupled directly to the fan such that the electrical
machine does not intrude into the inner fan chamber and is positioned entirely outside
the fan chamber to facilitate preventing interference with airflow within the fan
chamber. More specifically, the electrical machine includes a drive hub that is coupled
directly to the rotor assembly of the electrical machine and the rear plate of the
fan to facilitate rotation of the fan. The fluid circulating assembly also includes
a substantially planar controller assembly coupled radially outward from the stator
assembly. The controller assembly enables a low profile housing to cover the electrical
machine and the controller assembly such that the housing extends a minimal distance
from the fan rear plate and functions as a large single heat sink for both the stator
assembly and the controller assembly. As such, the fluid circulating assembly takes
up less space within a fluid circulating system and provides for additional space
for additional system components. Furthermore, the fluid circulating assembly contains
fewer overall components, which provides for a fluid circulating assembly that is
less expensive and easier to assemble than other known fluid circulating assemblies.
[0049] The apparatus, methods, and systems described herein provide a fluid circulating
assembly having increased efficiency, reduced noise, and an improved airflow distribution
through the fan. One advantage to breaking the controller assembly of the centrifugal
fan into modular board components includes enabling the controller assembly to be
favorably arranged around the outside diameter of stator assembly. Another advantage
is that the controller assembly and the stator assembly can share a common heat sink.
Yet another advantage is that the controller assembly can be arranged such that the
modular boards of the controller assembly can be separated by one or more of a particular
board function and a combination of heat making components. The exemplary embodiments
described herein provide apparatus, systems, and methods particularly well-suited
for HVAC centrifugal blowers.
[0050] Further, the embodiments described herein relate to fan assemblies that include a
backward curved fan and an axial flux electrical machine that reduces or prevents
airflow interference within the fan and improves the efficiency of the fluid circulating
assembly. More particularly, one embodiment includes a motor coupled to the fan such
that the motor does not intrude into the fan chamber. The methods and apparatus are
not limited to the specific embodiments described herein, but rather, components of
apparatus and/or steps of the methods may be utilized independently and separately
from other components and/or steps described herein. For example, the methods may
also be used in combination with a forward curved fan or blower assembly, and are
not limited to practice with only the backward curved fan as described herein. In
addition, the embodiment can be implemented and utilized in connection with many other
HVAC applications.
[0051] Although specific features of various embodiments of the disclosure may be shown
in some drawings and not in others, this is for convenience only. In accordance with
the principles of the disclosure, any feature of a drawing may be referenced and/or
claimed in combination with any feature of any other drawing.
[0052] This written description uses examples to disclose the invention, including the best
mode, and to enable any person skilled in the art to practice the invention, including
making and using any devices or systems and performing any incorporated methods. The
patentable scope of the invention is defined by the claims, and may include other
examples that occur to those skilled in the art. Such other examples are intended
to be within the scope of the claims if they have structural elements that do not
differ from the literal language of the claims, or if they include equivalent structural
elements with insubstantial differences from the literal languages of the claims.
[0053] In addition to the embodiments described previously and claimed in the appended claims,
the following is a list of additional embodiments, which may serve as the basis for
additional claims in this application or subsequent divisional applications.
[0054] Embodiment 1: A fluid circulating assembly having a rotation axis, said fluid circulating
assembly comprising: a fan impeller comprising an inlet ring and a rear plate that
together define a central fan chamber; an electrical machine comprising a rotor assembly,
a stator assembly, and a housing, said electrical machine coupled to said rear plate
such that said electrical machine is positioned entirely outside said central fan
chamber, said housing comprising a plurality of fins on a side of said housing opposite
said rear plate, said plurality of fins extending axially away from said stator assembly;
and a duct coupled to said housing, said duct covering a portion of said fins and
extending radially outward from said housing to said rear plate and towards an outer
edge of said rear plate, wherein said duct is configured to channel air over said
portion of said fins to facilitate cooling said electrical machine.
[0055] Embodiment 2: The fluid circulating assembly in accordance with Embodiment 1, wherein
said duct is substantially U-shaped in cross-section.
[0056] Embodiment 3: The fluid circulating assembly in accordance with Embodiment 1, wherein
said duct forms a converging taper extending radially from said housing toward said
outer edge of said rear plate.
[0057] Embodiment 4: The fluid circulating assembly in accordance with Embodiment 1, wherein
said duct further extends axially about said outer edge of said rear plate, wherein
said duct is configured to capture a portion of air ejected by said centrifugal fan
and channel the air radially inward over said portion of said fins to facilitate cooling
said electrical machine.
[0058] Embodiment 5: The fluid circulating assembly in accordance with Embodiment 1, wherein
said housing further comprises an annular center section, and at least two extension
portions extending radially outward from said annular center section.
[0059] Embodiment 6: The fluid circulating assembly in accordance with Embodiment 5, wherein
said fluid circulating assembly comprises a plurality of ducts, wherein each said
extension portion comprises a plurality of said fins, and wherein a respective one
of said plurality of ducts is coupled to a respective one of said at least two extension
portions.
[0060] Embodiment 7: The fluid circulating assembly in accordance with Embodiment 6, wherein
each one of said plurality of ducts extends between said center section and said outer
edge of said rear plate.
[0061] Embodiment 8: A method for assembling a fluid circulating assembly having a rotation
axis, said method comprising: providing a fan impeller including an inlet ring and
a rear plate that together define a central fan chamber; coupling an electrical machine
to the rear plate such that the electrical machine is positioned entirely outside
the central fan chamber, the electrical machine including a rotor assembly, a stator
assembly, and a housing, the housing including a plurality of fins on a side of the
housing opposite the rear plate, the plurality of fins extending axially away from
the stator assembly; and coupling a duct to the housing, the duct covering a portion
of the fins and extending radially outward from the housing to the rear plate and
towards an outer edge of the rear plate, wherein the duct is configured to channel
air over the portion of the fins to facilitate cooling the electrical machine.
[0062] Embodiment 9: The method in accordance with Embodiment 8, wherein coupling a duct
to the housing comprises coupling the duct to the housing, the duct including a substantially
U-shape cross-section.
[0063] Embodiment 10: The method in accordance with Embodiment 8, wherein coupling a duct
to the housing comprises coupling the duct to the housing, the duct forming a converging
taper extending radially from the housing toward the outer edge of the rear plate.
[0064] Embodiment 11: The method in accordance with Embodiment 8, wherein coupling a duct
to the housing comprises coupling the duct to the housing, wherein the duct further
extends axially about the outer edge of the rear plate, wherein the duct is configured
to capture a portion of air ejected by the centrifugal fan and channel the air radially
inward over the portion of the fins to facilitate cooling the electrical machine.
[0065] Embodiment 12: The method in accordance with Embodiment 8, wherein coupling an electrical
machine to the rear plate comprises coupling the electrical machine to the rear plate,
the housing further including an annular center section, and at least two extension
portions extending radially outward from the annular center section.
[0066] Embodiment 13: The method in accordance with Embodiment 12, wherein coupling a duct
to the housing comprises coupling a plurality of ducts to the housing, wherein each
extension portion includes a plurality of fins, and wherein a respective one of the
plurality of ducts is coupled to a respective one of the at least two extension portions.
[0067] Embodiment 14: The method in accordance with Embodiment 13, wherein coupling a plurality
of ducts to the housing comprises coupling the plurality of ducts to the housing,
wherein each one of the plurality of ducts extends between the center section and
the outer edge of the rear plate.
[0068] Embodiment 15: A fluid circulating assembly comprising:
an electrical machine comprising: a rotor assembly; a stator assembly; and a housing
comprising an endshield, said endshield comprising: an annular center section configured
to enclose said stator assembly; a plurality of fins extending axially away from said
stator assembly; and a plurality of axially extending T-shaped T-slots spaced about
a perimeter of said annular center section of said endshield.
[0069] Embodiment 16: The fluid circulating assembly in accordance with Embodiment 15, wherein
said endshield further comprises at least two extension portions extending radially
outward from said annular center section.
[0070] Embodiment 17: The fluid circulating assembly in accordance with Embodiment 16, wherein
each one of said plurality of axially extending T-slots is positioned at a respective
intersection between said at least two extension portions.
[0071] Embodiment 18: The fluid circulating assembly in accordance with Embodiment 15, wherein
each of said plurality of axially extending T-slots is identical in size and shape.
[0072] Embodiment 19: The fluid circulating assembly in accordance with Embodiment 15, wherein
a narrow opening in each of said plurality of axially extending T-slots faces radially
outward from said center section.
[0073] Embodiment 20: The fluid circulating assembly in accordance with Embodiment 15 further
comprising: an electrical machine support assembly comprising: a plurality of T-nuts,
each one of said plurality of T-nuts engaging with one of said plurality of axially
extending T-slots; a support bracket, wherein each one of said plurality of T-nuts
is releasably coupled to said support bracket via at least one mechanical fastener,
thereby enabling said electrical machine to be mounted on said support bracket using
said plurality of T-nuts at an infinite number of locations along said plurality of
axially extending T-slots, said plurality of T-nuts extending between said support
bracket and said electrical machine.
[0074] Embodiment 21: A method of assembling a fluid circulating assembly, said method comprising:
providing an electrical machine including a housing having a plurality of axially
extending T-slots spaced about a perimeter of the housing; slidingly coupling a T-nut
to each one of the plurality of axially extending T-slots; releasably coupling each
respective T-nut to a support bracket using at least one fastener, thereby enabling
the electrical machine to be slidingly coupled to the support bracket via the T-nuts
at an infinite number of locations along a length of the plurality of axially extending
T-slots.
[0075] Embodiment 22: The method in accordance with Embodiment 21, wherein providing an
electrical machine including a housing comprises providing the electrical machine
including the housing having an endshield, the endshield including an annular center
section configured to enclose a stator assembly, and a plurality of fins extending
axially away from the stator assembly.
[0076] Embodiment 23: The method in accordance with Embodiment 22, wherein providing the
electrical machine including the housing having an endshield comprises providing the
electrical machine including the housing having the endshield, wherein the endshield
includes at least two extension portions extending radially outward from the annular
center section.
[0077] Embodiment 24: The method in accordance with Embodiment 23, wherein providing the
electrical machine including the housing having an endshield comprises providing the
electrical machine including the housing having the endshield, wherein each one of
the plurality of axially extending T-slots is positioned at a respective intersection
between the at least two extension portions.
[0078] Embodiment 25: The method in accordance Embodiment 21, wherein providing an electrical
machine including a housing comprises providing the electrical machine including the
housing, wherein a narrow opening in each of the plurality of axially extending T-slots
faces radially outward from the housing.
1. A fluid circulating assembly having a rotation axis, said fluid circulating assembly
comprising:
a fan impeller comprising an inlet ring and a rear plate that together define a central
fan chamber;
an electrical machine comprising a rotor assembly, a stator assembly, and a housing,
said electrical machine coupled to said rear plate such that said electrical machine
is positioned entirely outside said central fan chamber, said housing comprising a
plurality of fins on a side of said housing opposite said rear plate, said plurality
of fins extending axially away from said stator assembly; and
a duct coupled to said housing, said duct covering a portion of said fins and extending
radially outward from said housing to said rear plate and towards an outer edge of
said rear plate,
wherein said duct is configured to channel air over said portion of said fins to facilitate
cooling said electrical machine.
2. The fluid circulating assembly in accordance with Claim 1, wherein said duct is substantially
U-shaped in cross-section.
3. The fluid circulating assembly in accordance with Claim 1, wherein said duct forms
a converging taper extending radially from said housing toward said outer edge of
said rear plate.
4. The fluid circulating assembly in accordance with Claim 1, wherein said duct further
extends axially about said outer edge of said rear plate, wherein said duct is configured
to capture a portion of air ejected by said centrifugal fan and channel the air radially
inward over said portion of said fins to facilitate cooling said electrical machine.
5. The fluid circulating assembly in accordance with Claim 1, wherein said housing further
comprises an annular center section, and at least two extension portions extending
radially outward from said annular center section.
6. The fluid circulating assembly in accordance with Claim 5, wherein said fluid circulating
assembly comprises a plurality of ducts, wherein each said extension portion comprises
a plurality of said fins, and wherein a respective one of said plurality of ducts
is coupled to a respective one of said at least two extension portions.
7. The fluid circulating assembly in accordance with Claim 6, wherein each one of said
plurality of ducts extends between said center section and said outer edge of said
rear plate.
8. A method for assembling a fluid circulating assembly having a rotation axis, said
method comprising:
providing a fan impeller including an inlet ring and a rear plate that together define
a central fan chamber;
coupling an electrical machine to the rear plate such that the electrical machine
is positioned entirely outside the central fan chamber, the electrical machine including
a rotor assembly, a stator assembly, and a housing, the housing including a plurality
of fins on a side of the housing opposite the rear plate, the plurality of fins extending
axially away from the stator assembly; and
coupling a duct to the housing, the duct covering a portion of the fins and extending
radially outward from the housing to the rear plate and towards an outer edge of the
rear plate, wherein the duct is configured to channel air over the portion of the
fins to facilitate cooling the electrical machine.
9. A fluid circulating assembly comprising:
an electrical machine comprising:
a rotor assembly;
a stator assembly; and
a housing comprising an endshield, said endshield comprising:
an annular center section configured to enclose said stator assembly;
a plurality of fins extending axially away from said stator assembly; and
a plurality of axially extending T-shaped T-slots spaced about a perimeter of said
annular center section of said endshield.
10. The fluid circulating assembly in accordance with Claim 9, wherein said endshield
further comprises at least two extension portions extending radially outward from
said annular center section.
11. The fluid circulating assembly in accordance with Claim 10, wherein each one of said
plurality of axially extending T-slots is positioned at a respective intersection
between said at least two extension portions.
12. The fluid circulating assembly in accordance with Claim 9, wherein each of said plurality
of axially extending T-slots is identical in size and shape.
13. The fluid circulating assembly in accordance with Claim 9, wherein a narrow opening
in each of said plurality of axially extending T-slots faces radially outward from
said center section.
14. The fluid circulating assembly in accordance with Claim 9 further comprising:
an electrical machine support assembly comprising:
a plurality of T-nuts, each one of said plurality of T-nuts engaging with one of said
plurality of axially extending T-slots;
a support bracket, wherein each one of said plurality of T-nuts is releasably coupled
to said support bracket via at least one mechanical fastener, thereby enabling said
electrical machine to be mounted on said support bracket using said plurality of T-nuts
at an infinite number of locations along said plurality of axially extending T-slots,
said plurality of T-nuts extending between said support bracket and said electrical
machine.
15. A method of assembling a fluid circulating assembly, said method comprising:
providing an electrical machine including a housing having a plurality of axially
extending T-slots spaced about a perimeter of the housing;
slidingly coupling a T-nut to each one of the plurality of axially extending T-slots;
releasably coupling each respective T-nut to a support bracket using at least one
fastener, thereby enabling the electrical machine to be slidingly coupled to the support
bracket via the T-nuts at an infinite number of locations along a length of the plurality
of axially extending T-slots.
16. The method in accordance with Claim 15, wherein providing an electrical machine including
a housing comprises providing the electrical machine including the housing having
an endshield, the endshield including an annular center section configured to enclose
a stator assembly, and a plurality of fins extending axially away from the stator
assembly.
17. The method in accordance with Claim 16, wherein providing the electrical machine including
the housing having an endshield comprises providing the electrical machine including
the housing having the endshield, wherein the endshield includes at least two extension
portions extending radially outward from the annular center section.
18. The method in accordance with Claim 17, wherein providing the electrical machine including
the housing having an endshield comprises providing the electrical machine including
the housing having the endshield, wherein each one of the plurality of axially extending
T-slots is positioned at a respective intersection between the at least two extension
portions.
19. The method in accordance with Claim 15, wherein providing an electrical machine including
a housing comprises providing the electrical machine including the housing, wherein
a narrow opening in each of the plurality of axially extending T-slots faces radially
outward from the housing.